Course Description

The field of rock physics represents the link between qualitative geologic parameters and quantitative geophysical measurements. Increasingly over the last decade, rock physics stands out as a key technology in petroleum geophysics, as it has become an integral part of quantitative seismic interpretation. Ultimately, the application of rock physics tools can reduce exploration risk and improve reservoir forecasting in the petroleum industry.

This course covers fundamentals of rock physics, ranging from basic laboratory and theoretical results to practical recipes that can be immediately applied in the field, presenting qualitative and quantitative tools for understanding and predicting the effects of lithology, pore fluid types and saturation, stress and pore pressure, fractures and temperature on seismic velocity and attenuation.

The importance and benefit of linking rock physics to geologic processes, including depositional and compactional trends as well as tectonic uplift and unloading, are key to this course, which demonstrates in detail how to build so-called rock physics templates that can be used to interpret both well log and seismic inversion data in terms of geological trends and reservoir properties. It is important in exploration and appraisal to extrapolate away from existing wells, taking into account how the depositional environment changes as well as burial depth trends. In this way rock physics can better constrain the geophysical inversion and classification problem in underexplored marginal fields, surrounding satellite areas, or in new frontiers.

In particular, we focus on how rock physics properties, fluid sensitivities and associated seismic signatures change as we go from soft sediments in the shallow subsurface to well consolidated rocks that have undergone more severe mechanical and chemical compaction, and even uplift and brittle deformation. Likewise, we show how seismic amplitudes can change drastically as we go from one depositional environment to another, for instance in a channel-levee complex as we go from central axis to the levee and overbank area.

The course includes practical examples and case studies, as well as suggested workflows, where rock physics models are combined with well log and prestack seismic data, sedimentologic information, inputs from basin modeling and statistical techniques to predict reservoir geology and fluids from seismic amplitudes.

Biography

Per Avseth is a geophysical consultant at G&G Resources in Oslo, Norway, and adjunct professor in geophysics at the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway. Per received his M.Sc. in Applied Petroleum Geosciences from NTNU in 1994, and his Ph.D. in Geophysics from Stanford University, California, in 2000. Per worked as a research geophysicist at Norsk Hydro in Bergen, 2001-2006, as a consultant at Odin Petroleum in Bergen, 2006-2012, and as a geophysical advisor at Spring Energy/Tullow Oil in Oslo, 2012-2016. Per’s research interests include applied rock physics and AVO analysis, for quantitative seismic exploration and reservoir characterization.

Tor Arne Johansen is a professor in reservoir geophysics at the University of Bergen and adjunct professor at University Studies at Svalbard (UNIS) in the Norwegian Arctic. Johansen has wide experience in rock physics and its use in improved seismic reservoir characterization. He has been a course instructor for EAGE and CSEG for several years.